1. Field of the Invention
The present invention relates to a safe and effective method for examining a colon which is generally non-invasive, substantially rapid, and which provides a continuous unobstructed view of the internal surface of the colon wall that facilitates detection and diagnosis of abnormalities in the colon anatomy.
2. Description of the Related Art
There are presently two conventional methods utilized most often for examining the colon to detect abnormalities such as tumors or inflammatory processes in the anatomy of the colon. One standard procedure is the colonoscopy, which consists of a direct endoscopic examination of the colon with a flexible tubular structure known as a colonoscope which has fiber optic capabilities at one end thereof. The colonoscope is inserted through the patient's anus and directed along the length of the colon, thereby permitting direct endoscopic visualization of the colon polyps and tumors and in some cases, providing a capability for endoscopic biopsy and polyp removal. Although it does provide a precise means of colon examination, colonoscopy is time-consuming, expensive to perform, and requires great care and skill by the examiner, thorough patient preparation including purgatives and enemas, and usually a moderate anesthesia. Moreover, since colonoscopy is an extremely invasive procedure, there is a significant risk of injury to the colon and the possibility of colon perforation and peritonitis, which can be fatal.
Another standard procedure for examining the colon involves a "barium enema" followed by a fluoroscopic and radiographic examination. In this procedure, a solution of barium sulfite alone or mixed with air is first injected into the patient's colon by means of an enema, and then a fluoroscopic and radiographic examination of the colon is performed. This examination requires detailed observation by a radiologist, who must palpate the patient's abdomen and repeatedly reposition the patient for the taking of a first set of x-rays. After these initial x-rays are completed, the patient evacuates the barium mixture and additional x-rays are taken. The total examination procedure can be of considerable duration, lasting from 20 minutes to 11/2 hours, and is very uncomfortable and demanding both for the patient as well as the radiologist and x-ray technician. During the examination, the patient may experience numerous difficulties such as problems retaining the barium mixture, pain associated with palpation, and colon spasms. It is also possible for the colon to become impacted with barium, leading to severe constipation and interference with later diagnostics, thereby requiring the barium to be fully purged using powerful and sometimes dangerous laxatives. This purging of the barium may also in rare instances result in colon perforation with barium peritonitis, which is a lifetime debilitating and potentially fatal complication,
Because of the significant difficulties and potential complications involved with both of the conventional procedures for examining the colon, there is still a need for a method of examining a patient's colon which provides a precise and accurate visualization of the colon anatomy to detect abnormalities, is easy to conduct by medical personnel and generally non-invasive compared with conventional procedures, and which involves minimal discomfort to the patient.